A REVOLUTIONARY discovery could pave the way for a simple blood test to help in the battle against old age.

The test can predict not only our long-term health but the rate at which we will age, scientists have found.

The discovery, led by British researchers, could lead to powerful new treatments and drug therapies to tackle conditions linked to getting older, from bone problems to heart disease.

A study of twins led by King’s College, London, found that key metabolites in blood, which are chemical “fingerprints” left behind after molecular changes before birth or in infancy, can provide the vital clues.

They could point to a person’s long-term overall health and rate of ageing in later life.

A technique called metabolomic profiling has revealed a collection of 22 of these fingerprints linked to ageing.

One of them, linked to ageing traits such as lung function and bone mineral density, is also strongly associated with birth weight. This is already a well-known developmental factor which determines healthy ageing.

The new finding suggests that levels of this novel metabolite, which may be determined in the womb and affected by nutrition during development, could lead to accelerated ageing in later adult life.

Scientists say it is possible that these markers of ageing can be identified with simple blood tests in the future, which may provide further clues to the ageing process and could pave the way for development of therapies to treat age-related conditions.

Ana Valdes, lead researcher from King’s, said: “Human ageing is a process influenced by genetic, lifestyle and environmental factors, but genes only explain a part of the story. Molecular changes that influence how we age over time are triggered by epigenetic changes. This study has for the first time used analysis of blood and epigenetic changes to identify a novel metabolite that has a link to birth weight and rate of ageing.”

She added: “This unique metabolite, which is related to age and age-related diseases, was different in genetically identical twins that had very different weight at birth. This shows us that birth weight affects a molecular mechanism that alters this metabolite.

This study has for the first time used analysis of blood and epigenetic changes to identify a novel metabolite that has a link to birth weight and rate of ageing

Ana Valdes, researcher

“This may help us understand how lower nutrition in the womb alters molecular pathways that result in faster ageing and a higher risk of age-related diseases 50 years later. Understanding the molecular pathways involved in the ageing process could ultimately pave the way for future therapies to treat age-related conditions.

“As these 22 metabolites linked to ageing are detectable in the blood, we can now predict actual age from a blood sample pretty accurately and in the future this can be refined to potentially identify future rapid biological ageing in individuals.”

Published in the International Journal of Epidemiology, the study analysed blood samples donated by more than 6,000 twins, they identified 22 metabolites directly linked to chronological age. The concentrations of the metabolites were higher in older than in younger people.

Professor Tim Spector, head of the department of twin research at the university, said: “Scientists have known for a long time that a person’s weight at the time of birth is an important determinant of health in middle and old age, and that people with low birth weight are more susceptible to age related diseases.

“So far the molecular mechanisms that link low birth weight to health or disease in old age had remained elusive, but this discovery has revealed one of the molecular pathways involved.”

The researchers at Kings College have linked lower weights at birth to age-related illnesses